In the WCDMA communication system, currently there is an application that a cell is divided into a plurality of sectors according to various network operation requirements, such as OTSR (Omni-Transmission Sectorized Receive) mode, wherein a downlink signal of one cell is transmitted in the whole cell while an uplink signal is received from a plurality of sectors. Since the uplink transmission power of the WCDMA system is limited, in this way, a larger network coverage in a flat area can be realized with less cost, or a network coverage in a complex urban district can be realized with flexibility, the number of cells is reduced and network configuration is simplified. Other modes, such as the cell portion mode defined in the 3GPP (the 3rd Generation Partnership Project), the simulcast mode in the related filed, also employ sectorized method. The sectorized method can improve the uplink receiving ability and system capacity and is applied to the commercial network of WCDMA R99.
In the new version R6, the HSUPA service is introduced, and the mobile station using the HSUPA service is referred to as HSUPA UE (HSUPA User Equipment), of which the key technology is that the base station (Node B) needs to schedule the load of the uplink of the HSUPA UE. The load size can be measured using RTWP (Received Total Wideband Power), the more the elevation of the RTWP, the higher the load. According to 3GPP 25.433, the system will set an RTWP reference value (Reference Received Total Wideband Power) and an RTWP target value (Maximum Target Received Total Wideband Power), respectively referred to as RTWPref and RTWPtarget, wherein RTWPref corresponds to the system receiving noise (background noise) when there is no any mobile station (UE: User Equipment) in the current cell, if the RTWP of the current system is RTWPcurrent, then the current system load can be expressed as:L=(RTWPcurrent−RTWPref)/RTWPcurrent  (1).
It can be seen from Equation (1) that, when the current RTWP of the system is raised to twice (3 dB) of the background noise, the system load is 0.5 (i.e., 50%); when the current RTWP of the system is raised to 4 (6 dB) times of the background noise, the system load is 0.75 (i.e., 75%). RTWPtarget corresponds to the allowable load used by the system, for instance, when RTWPtarget is 4 times (6 dB) of RTWPref, the allowable load used by the system is 0.75. The system makes a greatest effort to make RTWP not more than RTWPtarget when scheduling the load. One conventional dispatching process is: Node B calculates the rest available load according to the measurement results of RTWP. The estimation result of the SIR (Signal to Interference Ratio) of each HSUPA UE is used to calculate the load consumed by each HSUPA UE. Then, the rest available load is scheduled to each HSUPA UE. Generally, the calculation of the load dispatching is performed according to the whole cell and the HSUPA UE within the cell, wherein the method of load estimation according to the SIR of the HSUPA UE is:L=SIR/(1+SIR)  (2)
wherein L is the load of the HSUPA UE, SIR is the SIR of the HSUPA UE.
FIG. 1 is the schematic diagram of the conventional HSUPA scheduling method for a conventional cell. In the conventional HSUPA scheduling method, each HSUPA UE has only one SIR estimation in each cell, the scheduler utilizes this SIR to calculate the load occupied by the UE. The conventional cell also has only one value, and the dispatcher directly utilizes this value to calculate the cell load. In this case, HSUPA function runs properly and the throughput of the HSUPA is that of one cell. In 3GPP R6 version, the maximum HSUPA throughput of such a cell is 5.76 Mbps. The conventional HSUPA scheduling method is performed on the cell-base.
However, in the sectorized receiving mode, the uplink signals are received by the antennas of the base station in multiple sectors, the signals of the multi-sector antennas are combined in the baseband processing. For an HSUPA scheduler, various sectors of one cell may have different RTWPs, and how to determine the RTWP required by the cell scheduling becomes a problem; the signals of HSUPA UEs are also distributed differently in various sectors, thus the relationship between the load of the HSUPA UE and the RTWP of each sector cannot be distinguished only depending on the estimation of SIR by the HSUPA UE, which makes the scheduler disordered.
FIG. 2 is the schematic diagram of the conventional HSUPA scheduling method for a sectorized cell in the prior art. In the sectorized cell, each sector of the base station has its own antenna and different RTWP. In this case, if the conventional HSUPA scheduling method is utilized, the RTWPs of a plurality of sectors must be combined into one RTWP of the cell. In order to maintain system stability and prevent over elevation of RTWP, in common practice the maximum RTWP of the plurality of RTWPs is selected as the cell RTWP, otherwise a large overload rate will be induced. The shortcoming of the practice is that, when the resource of one sector has been distributed and the RTWP has achieved the target value, even if there is still resource in other sectors and RTWP is still comparative low, the resource can not be distributed to the HSUPA UE, which will result in resource waste and throughput limitation. Moreover, when the conventional HSUPA scheduling method is used in a sectorized cell, the SIR of the HSUPA UE has only one value, thus if the HSUPA UE is in a neighboring region of sectors, the receiving of the uplink multi-sector antenna has a diversity gain, so as to make the RTWP comparatively low, but the SIR is still about the same as that without diversity gain, thus the sum of HSUPA UE loads calculated based on the SIRs reaches the full load of the cell, but the load calculated based on the RTWPs is still comparative small, which results in that the conventional HSUPA scheduling algorithm will not distribute resource to the HSUPA UE any more, which also results in a large underload and throughput limitation.
According to the conventional method in the prior art, the poor relevancy between RTWP and SIR will result in a large overload or underload, and schedule is performed on the basis of cell, the throughput is equal to that of a conventional cell, however, in theory, sectorized mode may make the throughput improved by several times compared with that of a conventional cell. Therefore the exiting HSUPA scheduling method shall be improved.